Refraction and Lenses

Transcription

1 Refraction and Lenses Name Q.(a) Figure shows a ray of light entering a glass block. (i) The angle of incidence in Figure is labelled with the letter i. On Figure, use the letter r to label the angle of refraction. () Figure 2 shows the protractor used to measure angles i and r. What is the resolution of the protractor? Tick ( ) one box. degree 5 degrees 0 degrees ()

2 (iii) The table shows calculated values for angle i and angle r from an investigation. Calculated values sin i = 0.80 sin r = 0.50 Use the values from the table to calculate the refractive index of the glass. Use the correct equation from the Physics Equations Sheet. Refractive index =... (2) (b) The diagrams below show a ray of light moving through glass. Which diagram correctly shows what happens when the ray of light strikes the surface of the glass at the critical angle? Tick ( ) one box. () (c) A concave (diverging) lens is fitted into a door to make a security spyhole. Figure 3 shows how this lens produces an image.

3 (i) State one word to describe the nature of the image in Figure () Use data from Figure 3 to calculate the magnification of the image. Use the correct equation from the Physics Equations Sheet. Magnification =... (2) (iii) What is another use for a concave lens? () Tick ( ) one box. A magnifying glass Correcting short sight To focus an image in a camera (Total 9 marks)

4 Q2.(a) Figure shows a diagram of a human eye. Label the parts A and B on Figure. (2) (b) State the function of the iris () (c) Figure 2 shows light rays travelling into the human eye. (i) Give the name of the defect of vision shown in Figure 2. () A concave (diverging) lens can be used to correct the defect of vision shown in Figure 2. Complete the ray diagram in Figure 3 to show how a concave lens produces an image of the object. Use an arrow to represent the image.

5 (3) (d) It is important that muscles can change the power of the lens in the eye. State why.... () (e) The power range of an eye lens is the difference between the maximum and minimum power of the lens. Figure 4 shows how the power range of an eye lens changes with age.

6 (i) Use data from Figure 4 to calculate the maximum change that can happen to the focal length of the eye lens for a 60-year-old person. Use the correct equation from the Physics Equations Sheet. Give the unit. Maximum change in focal length =... unit... (2) Compare the change in power range of the eye lens between the ages of 0 and 30 with that between the ages of 50 and 70. (3) (Total 3 marks)

7 M.(a) (i) degree (iii).6 allow mark for correct substitution, ie 0.80 / 0.5 provided no subsequent step shown working showing.59(9..) scores zero 2 (b) 2 nd diagram ticked (c) (i) any one correct description: upright virtual diminished. treat multiple words as a list 0.25 allow mark for correct substitution, ie / 4 or 5 / 20 provided no subsequent step shown ignore any unit 2 (iii) Correcting short sight [9]

8 M2.(a) (b) A = suspensory ligament B = retina to control the amount of light entering the eye or to control the amount of light incident on the retina allow change the size of the pupil (c) (i) short sight or myopia accept near sight any 2 correct construction lines: construction lines may be dotted or solid construction lines must pass correctly through the lens treat more than 2 construction lines as a list for marking 2 upright image drawn at correct location image must be to the left of the lens upright orientation of image must be clear the image line can be dotted or solid

9 ignore any arrows on construction rays (d) to focus light from objects at different distances accept can see objects (clearly) at different distances. to focus light on the retina is insufficient (e) (i) 0.5 metre(s) / m the unit is not an independent mark an answer 0.5 without a unit or with an incorrect unit scores mark or a substitution 2 = / f with the unit metre(s) / m scores mark 2 0 to 30 decreases linearly or at a constant rate accept from 0 to 30 the decrease is 2.6 / 2.7(D) 50 to 70 falls less rapidly after 60 years accept it decreases at a decreasing rate accept from 50 to 70 the decrease is 3.3 / 3.4(D) 0 to 30 decrease is less than 50 to 70